Method of impregnating timber.



G. B. SHIPLEY.

METHOD OF IMPREGNATING TIMBER. APPLICATION FILED JUNE 27, 1914.

1,163,270, Patented Dec. 7, 1915.

WITNESSES INVENTOR om n,

' GRANT B. snrrLEY, or PITTSBURGH, PENNSYLVANIA.

Application filed June 27, 1914. Serial No. 847,730.

70 all whom it may concern:

Be it known'that I, GRANT B1. SHIrLEr, a resident of Pittsburgh, in the county of Allegheny and State of Bennsylvania, have invented a new and useful Improvement in Methods of Impregnating Timber, of which the following is a specification.

This invention relates to a' method of preserving timber, and is more particularly applicable to the treatment of railroad ties with a suitable preserving solution or composition.

The main object of the invention is toprovide amethod for treating ties and other timber whereby a thorough penetration of the wood with aminimum amount of solution is secured, in order to reduce the weight of the ties or other timber, and whereby electric conductivity 'of the tie or timber, the leeching or evaporation of the preserving solution, and corrosion of the spikes and tie plates is prevented, as well as other objects and advantages which will hereinafter more fully appear.

Railroad ties have heretofore been treated with several preserving solutions, the principal ones being zinc chlorid and a coal tar product, universally calledv creosote in the trade. The creosote treatment is rather expensive, while the vzinc chlorid treatment, while less expensive isopen to the objection that if the timber is thoroughly impregmated with the solution it is left very heavy,

' of spikes, tie plates, etc.

The object of the present invention is to providea method of treating timbers, and

particularly railroad ties, whereby the foregoing objections are overcome.

Generally stated, it conslsts the ties or other timber, first with zinc METHOD BF IMPREGNATING TIMBER.

Speclficdtion of Letters Patent.

' in treating Patented Dec. a, rare.

ehlorid or other antiseptic salts, and afterward with a water-proofing composition which may be the creosote above referred to or other coal tar product or a petroleum product, the treatment being so eife'cted that the zinc chlorid does not produce the evil efi'ects above noted, and the amount of preserving solution required is reduced to a minimum.

The method maybe carried out by various forms of apparatus, and the accompanying drawingshows merely diagrammatically a single form' or arrangement of apparatus by means of which the method may be carried out. i

The apparatus may be of any design, but must comprise a suitable treating cylinder,

an equalizing cylinder 2 two storage tanks, one tank 3 or contaimng water-proofing composition; a pair of pressure and measuringtanks, one tank 5- for the preserving solution and the other tank 6 for the waterproofing composition, said tanks bein mounted on scales indicated at 1.1, in or er to secure accurate measurement of the solution or waterproofing com: pound absorbed by thetimber; a compressor and vacuum pump 7; a condenser 8; a centrifugal pump 9-; and an air pressure pump 10, together with suitable piping and valves connecting these parts arranged to circulate the solution and compound as required, and

shown at 1, in which the timber is treated;

the zinc chlori'd v or other preserving solution and the other tank 4 for containing the creosote or other suitable coils in the retort'and the several tanks for maintaining the necessary tern .perat ure' for the best treatment of the timher, which coilswillbe connected up to a boiler or other suitable means of steam pressure, not shown Preferably the equalizing cylinder 2 and Waterproofing composition tank L are elevated above the treating cylinder 1 so that the preserving solution and waterproofing composition will flow by gravity. into the treating cyli'nden. While in the drawing only a single treating'cylinder is shown as supplied from the equalizing cylinder, storage tanks and pressure tanks, it is obvious that any desired number of such cylinders can-be. connected by a suitable system of As shown a pipe 12 leads from the bottoms of the tanks 2, 3 and 4, to the bottom of treating cylinder 1 and also to the pressure tanks 5 and 6, having a branch connecting to each of the latter. The air pressure pump 10 has its outlet 13 branched and connected to the tops of the pressure tanks 5- and 6. The centrifugal pump 9 has its inlet connectedto the pipe 12 and its outlet connected by by-pass pipe 14L to the branch 12 running from pipe 12 to the equalizing tank 2. 'lhe pump 7 is arranged to act either as an air pressure or as a suction machine, being shown as a duplex compressor, having discharge pipes 15 connected through pipes 16 and 17 to the top of the treating cylinder 1 and being provided with a by-pass 18 in which is located the condenser 8 and by means of which said pump is enabledv to act as a suction or vacuum ump.

Suitable valves are located in various positions in the pipes of the system in order to effect the circulation of the preserving solution, the waterproofing composition and the air, as will hereinafter appear.

The treatment of the timber according to this process consists of two main steps or operations, viz., first treating the timber with the preserving solution and afterward with the waterproofing compound. Before starting the system the cylinder 2 is filled with preserving solution from the storage tank 3, which is done by opening valves 19, 14 and 20 and closing valves 21 and 22, and starting the centrifugal pump 9. The pres sure tank 5 is also filled with preserving solution from storage tank 8, and the pressure tank 6 is filledwith water proofing compound from the storage tank 6. The cylinder 2 holds a little more preserving solution than is necessary to fill the treating cylinder 1.

The timber to be treated, indicated at 23, is placed in the treating cylinder 1, and the latter is then sealed. The pump,7 is'then started and valves 24, 25, 26 and 27 are opened and the valve 27 is closed, and the pump 7 acting as an air compressor forces compressed air into the equalizing cylinder ,2 above the preserving solution therein and also into the treating cylinder 1, where the air penetrates the pores or cells of the wood being treated.

When the pressure in the treating cylinder 1 and equalizing tank 2 reaches from 50 to 100 lbs. per sq. in. (depending upon the kind of timber being treated) the compressor 7 is stopped and the valves 20, 22, 28 and 29 are opened whereupon; the preserving solution flows by gravity from the cylinder 2 into the treating cylinder 1, displacing the air in treating cylinder 1 which passes through pipes 17 and 17 to the top of cylinder 2, without reducing the air-pressure and thus saving pumping. Then the valves 20 and 28 are closed and the pressure on the top of cylinder 2 may be permitted to escape, such as through a bleed valve 30. The air pressure pump 10 is then started, the valves 13 and 5 are opened and the valve 29 closed. The pump 10 compresses the air on top of the preserving solution in tank 5 and forces the solution into the treating cylinder 1 against a pressure which at the beginning is from 50 to 100 lbs. per in., as above stated, and gradually increasing up to from 125 to 225 lbs. per inch, (depending upon the character of timber being treated) until no further solution-can be forced into the timber. The cylinder 1 is then drained, which is done by opening the necessary valves and by means of the air compressor pump 7 blowing the solution out of treating cylinder 1 and back into the cylinder 2. In the arrangement shown this is effected by closing valve 27 opening valve 27 and closing valves 29, 25 and 21, and opening valves 26, 24,- 28 and 29, whereby the solution isforced by the pump 7 back into the cylinder 2.

As soon as the treating cylinder 1 has been drained of the preserving solution the valves '28, 26, 25 and 27 are closed and the valves 24, 29, 31 and 27 are opened, and the pump 7 is again started, now acting as a suction or vacuum pump to produce a quick vacuum in the treating cylinder 1 and withdraw from the timber from 30 to 50% of the fluid previously forced into the pores of thewood, which is collected in the bottom of cylinder 1 and is returned through pipe 32 to the equalizing cylinder 2. The fluid withdrawn from the wood, by forming 'a partial vacuum in the treating cylinder, is somewhat weakened, and the solution remaining therein is correspondingly strengthened by the processes of introducing and withdrawing the solution. In the preliminary step compressed air was forced into the pores of the wood, and was trapped in such pores at the time the preserving solution was let into the treating cylinder 1 from the cylinder 2, and was further compressed when the preserving solution was forced into the pores of the wood by means of the pressure pump 10. As soon as the pump 7 begins to act as a suction pump this trapped air expands and assists in forcing out of the wood the. surplus water or weak solution, as a consequence of which the cells of the wood instead of being left full of water which it is left by previous processes of treating the same with zinc chlorid or similar preserving liquid, and furthermore since it contains a much smaller percentage of water is a better electrical insulator.

During the foregoing operations the treating cylinder and its contents are mamtained at a temperature of from 140 to 180 Fahrenheit, by means of the steam coil 33 in the bottom of said retort,or if desired by additional coils 34 in the cylinder 2 or coils 35 in the tank 3. The timber is then subjected to the second operation, viz., with the waterproofing composition from the tank 4. This is efiected by closing the previously open valves and opening valves 28, 29, 21'

and 36, whereupon the waterproofing composition fiows by gravity from tank 4: and fills the treating cylinder 1. All connections to the treating cylinder 1 are then closed and valve 13 to the pressure tank 6' and valve 6 from pressure tank 6 are opened, and the air pressure pump 10 is again started. This creates pressure upon the waterproofing composition in tank 6 and forces additional waterproofing composition from said tank into the treating cylinder 1 and into the timber contained therein. This pressure is continued until the timber has absorbed convert the pump 7 into a suction or vacuum pump, and a vacuum is produced in the treating cylinder 1 in order to withdraw the surplus waterproofing composition from the timber, dry the latter, and prevent dripping, the surplus waterproofing composition being returned to the tank 6 through pipe 37. During the second treatment the waterproofing composition of coal tar or petrole um products is kept at a high temperature, substantially" from 180 to 300 Fahrenheit,

which can be effected by the heating coils 33 in the bottom of treating cylinder 1, or if desired, by additional heating coils 38 in the tank 4 and 39 in the pressure tank 6. As a consequence, when the timber is removed from the treating cylinder and cools, the waterproofing. composition on its exterior sets or hardens and therefore seals the cells of the timber and prevents the leeching out and evaporation of the preserving solution, with which the timber was treated in the first place, and also prevents the entrance of water and moisture into the timber and increases its chemical-life.

By means of the foregoing method, timbers, and particularly railroad ties, can be expeditiously treated and in such manner that the entire body of the timber is imvents loss of the preserving solution due to leeching and evaporation, but also when as usual the ties aregained and bored before treatment said waterproofing composition so coats the exterior of the tie and interior of the spike holes so that'the plates and spikes are prevented from coming into contact with the zinc chlorid solution, which will prevent the corrosion of spikes and tie plates which occurs when the ties are treated with zinc chlorid, according to old processes. The process also gives a material saving in the cost of treatment as compared with the usual creosote treatment.

The process described is adapted for treating any character of wood or timber with a preserving solution and a waterproofing compound. While it has been described particularly for the treatment of railway ties, it is obvious that the process can be applied equally well to the treatment of paving blocks and various other forms oftimbers which in use are subject to conditions which are likely to cause decay.

What I claim is:

1. The process of treating wood consisting in subjecting the wood to air pressure, and without relieving the air pressure subjecting the same to a bath of a preserving composition under a pressure higher than the air pressure, withdrawing the preserving composition .and immediately subjecting the wood to a partial vacuum, thereby extract ing a portion of water and composition, and then coating the wood with a waterproofing composition.

2. The process of treating wood consisting in subjecting-the wood to air pressure, and without relieving the. air pressure subjecting the same to a bath of a preserving composi tion under a pressure higher than the air pressure, withdrawing the composition, and immediately subjecting the wood .to a partial vacuum, thereby extracting a portion of water and composition, and then subjecting the wood to a waterproofing composition under pressure. I

3. The process of treating wood consisting in subjecting the wood to air pressure, and without relieving the air pressure subjecting the same to a bath of a preserving composition under a pressure higher than the air pressure, withdrawing the composition, and immediately subjecting the wood to a parits tial vacuum, thereby extracting a portion of Water and composition, subjecting the wood to a Waterproofing composition under pressure, and then withdrawing a portion of the Waterproofing composition therefrom under a partial vacuum.

In testimony whereof, I have hereunto set my hand.

GRANT B. SHIPLEY. Witnesses:

WILLIAM B. VVHARTON, ELBERT L. HYDE. 

